# vim:sw=8:ts=8:si:et


This is the software for the tuxgraphics.org
ethernet remote device with an attached sensirion sht11 sensor.
This is a calibrated sensor for both humidity and temperature.
No additional external components are needed (not even a resistor). 
See http://tuxgraphics.org/electronics/

Copyright of most software and all diagrams: Guido Socher

Copyright of enc28j60.c/enc28j60.h Pascal Stang (http://www.procyonengineering.com/)
          and small modifications by Guido Socher

License for the webserver software: GPL V2
See http://www.gnu.org/licenses/gpl.html

License for the sensirion_protocol* files:
Use as you like without warrenty for anything.
---------------------------------------------------------------------------
Sensor connection

Sensor GND --- GND  (available on the digital IO port of the web-server board)
Sensor Vcc --- 3.3V (available on the analog port of the web-server board)
Sensor SCK  --- PD0 (available on the digital IO port of the web-server board)
Sensor Data --- PD1 (available on the digital IO port of the web-server board)

---------------------------------------------------------------------------

 All parts needed to build this AVR ethernet solution can be ordered from 
 http://shop.tuxgraphics.org/                                          

!! READ THIS FIRST !!
---------------------
! Edit the file main.c and change the 2 lines:
! static uint8_t mymac[6] = {0x54,0x55,0x58,0x10,0x00,0x26};
! static uint8_t myip[4] = {10,0,0,26};


For the first device you build you will not need to change the mymac line.
But you will probably need to change the IP address (myip). It must be a
free address from the address range in your home network.

There is a range of private addresses (not routed on the public internet)
which you can use:
Netmask          Network Addresses
255.0.0.0         10.0.0.0 - 10.255.255.255
255.255.0.0       172.16.0.0 - 172.31.255.255
255.255.255.0     192.168.0.0 - 192.168.255.255

Example: you wlan router might have 192.168.1.1, your PC might have
192.168.1.2. This means you could e.g use 192.168.1.10 and leave some
room for more PCs. If you use DHCP then make sure that the address it not
double allocated (exclude it from the DHCP range).

You need an avr-gcc development environment in order to compile this.
You need at least avrlibc-1.4.x !! The atmega88/atmega168 will not work with earilier 
versions.

Edit the beginning of the make file. And adjust those lines according to the
CPU you use (atmega168, atmega88 or atmega328p):

MCU=atmega168
DUDECPUTYPE=m168
#
#MCU=atmega88
#DUDECPUTYPE=m88
#


To compile the final software use the command:
make

The above command will compile the following hex files:
eth_rem_dev_tcp.hex  test0.hex  test1.hex  test2.hex  test_readSiliconRev.hex

The command
make load

The last command will run something like: 
   avrdude -p m168 -c avrusb500 -e -U flash:w:eth_rem_dev_tcp.hex

! Note your programmer might interfer with the enc28j60! For the avrusb500
! with 30cm cable you can normally leave the cable on. For all other programmers
! it is however saver to remove the programmer cable and power down/up the device.
! This is because the SPI interface is used for loading of the software and 
! communication to the enc28j60.

To see a list of all possible build targets run the command:
make help

Selecting the right clock source
--------------------------------
Tuxgraphics hardware sold as of march 2007 is prepared to use the clock
signal from the enc28j60. To use this you need to change the 
low fuse byte once from 0x62 to 0x60:
avrdude -p m168 -c avrusb500 -u -v -U lfuse:w:0x60:m

or just type in your Linux shell:
make fuse

After this the fuse settings should be as follows:
lfuse reads as 60
hfuse reads as DF
efuse reads as 1


Selecting the right clock source for older hardware (pre march 2007)
--------------------------------------------------------------------
Note: Older hardware must use the atmega88 internal clock (8MHz).
Don't try to change any fuse bytes on the older hardware!! You will
not easily be able to undo such an operation on the older hardware.
It will completely halt and nothing will work anymore.
The older hardware must use the factory default fuses which look like this:
low fuse:  0x62
high fuse: 0xdf
ext. fuse: 0x01

If you are unsure what the current fuse setting are on the atmega88 
then you can read the fuse settings with a command like: 
          avrdude -p m88 -c avrusb500 -v -q
      The result should be this (default factory settings):
          avrdude: safemode: lfuse reads as 62
          avrdude: safemode: hfuse reads as DF
          avrdude: safemode: efuse reads as 1


Compilation on non-Unix systems
-------------------------------
Please use the provided Makefile 
It will also work under Windows except for the loading
of the software. That is compiling will work but not 
"make load". Use then whatever tools and commands to download
the resuting .hex file into the micrcontroller
Do not forget to adjust the fuese (see above).

Loading the test software
-------------------------
Test of the atmega88/atmega168:
make test0.hex
make load_test0

This will case a LED on PB1 to blink with 1Hz

---------------
Edit the file test1.c and change the lines (see description above):
static uint8_t mymac[6] = {0x54,0x55,0x58,0x10,0x00,0x26};
static uint8_t myip[4] = {10,0,0,26};

make test1.hex
make load_test1

The program will perform a LED test for the LEDs on the magjack.
The LEDs will go on and off after startup and then the green LED
should stray on indicating that the link is up. When you ping the circuit
it will answer. The yellow LED should blink when the a packet arrives.
The red LED on PB1 should go on/off with every ping packet.

---------------
Edit the file test2.c and change the lines (see description above):
static uint8_t mymac[6] = {0x54,0x55,0x58,0x10,0x00,0x26};
static uint8_t myip[4] = {10,0,0,26};

make test2.hex
make load_test2

The green LED on the magjack should go on indicating that the link is up.
When you ping the circuit it will answer. The yellow LED should blink when 
the a packet arrives.
Point your web browser to the
device: http://10.0.0.26
You should see a web page that says "OK, it works".

A simple web server example (not the eth_rem_dev_tcp.hex)
---------------------------------------------------------
The test_readSiliconRev.c (compiles to load_readSiliconRev.hex) reads 
the enc28j60 silicon revision and displays it. 
You can use it as a base for a simple application
where you want to just read data (e.g thermometer)

make 
make load_readSiliconRev

Read via webbrowser:
http://10.0.0.26

will display a webpage with:
ENC28J60 silicon rev is: 4

Using the eth_rem_dev_tcp with TCP/HTTP 
---------------------------------------
Point your web browser to
http://10.0.0.26   (or what ever IP address you have given your hardware)

You should get a web page like this:

---------------------------------
Sensor @26

temperature  : 24.1'C [75.3'F]
rel. humidity: 61%
dew point    : 15.4'C [59'F]

refresh page
---------------------------------
version 3.0

The page reloads itself automatically every 5 min.

Messages form a Network analyser
--------------------------------
traffic_XXX.txt and traffic_XXX.cap are
decoded and binary messages of the communication with the
eth_rem_dev_tcp. This will help you to understand the code.

Revision history
----------------
2007-09-11: version 3.0 -- first public version. Based on eth_rem_dev_tcp-2.8.tar.gz
2008-12-21: version 3.1 -- update of Makefile for atmega168, auto-refresh the page every 5min